Polyquinoline polymers are useful in a broad range of electronics and microelectronics applications, including planarizing dielectric layers in integrated circuit manufacture, passivation layers, as protective coatings and potting compounds, as adhesives, as resins for printed wiring board fabrication, as dielectric materials, as coating applications for liquid crystal displays, flat panel television, solar windows, and the like, as fibers, and as high-strength stable films.
Methods of preparing polyquinolines by the Friedlander condensation reaction are disclosed in U.S. Pat. No. 4,000,187 which issued to J. Stills on Dec. 28, 1976. By means of the Friedlander reaction, polyquinoline polymers are prepared from the reaction of what is called a type AA compound, i.e., an aromatic amino carbonyl which contains two sets of ortho-amino carbonyl functions attached to an aromatic nucleus, with what is called a type BB compound, i.e., a bis-methylene ketone compound. Polyquinoline polymers may also be prepared from type AB compounds, i.e., compounds which incorporate both an ortho-amino carbonyl function and a methylene ketone function on an aromatic nucleus.
In conducting the Friedlander reaction, the AA and BB or AB type compounds are typically reacted in the presence of a phosphate catalyst in m-cresol solvent. Such phosphate/cresol catalyst systems are expensive and cresol is difficult to work with.
It is desired to provide a process for forming polyquinolines which is economical and which does not require cresol as a solvent.